Brain-Sync

A completely local semantic web clipper for Chrome. Save any page, then search it later by what it means. No account, no server, nothing ever leaves your machine.

Chrome extension (Manifest V3), no build step, zero dependencies. Pages are chopped into ~300 word chunks on paragraph edges and stored as vectors in IndexedDB.

The default engine needs no downloads: stemmed tokens run through a signed hashing trick into a 512-dim vector with sublinear term frequency, L2 normalised, compared with cosine. On top sit boosts for token overlap, title matches and exact phrases, plus a coverage factor so a rare unknown word can’t randomly match an unrelated page. Drop transformers.js into vendor/ and it upgrades to real all-MiniLM-L6-v2 embeddings, falling back to lexical when the model is missing.

Clip from the popup, right click menu, or Cmd+Shift+Y. Domain filter and min score on any query, recent feed, per-domain tally, JSON export/import.